Certainly, the GM can't reveal everything; he has to hold back to some extent, but generally, he's very honest.
It's worth noting that big names like Trevor Zegras, Martin Necas, Rutger McGroarty, Patrik Laine, and others have yet to be moved. There have been no announced trades at that level.
Also, remember that Hughes completed trades for forwards in the last two years, before or during the draft, acquiring Kirby Dach and Alex Newhook.